1. Field of the Invention.
The present invention relates to the preservation and improved effectiveness of chemicals used to kill or otherwise regulate the growth of undesirable living bodies in an aqueous environment. In particular, it relates to processes for applying a coating of fat to chemical growth regulators and insecticides.
2. Description of the Prior Art.
In the application of chemicals or biologicals to control insects, many of the chemicals employed are sensitive to biodegradation. The Zoecon growth regulator ZR-515 is an example. By a process of microencapsulation this chemical has been successfully protected from biodegradation (Zoecon SR-10). The control of particle size and density, however, is also required for optimal aquatic effectiveness.
This Zoecon process of microencapsulation was tried on a bacterial endotoxin without success, thus indicating the complexity of the problem since the encapsulation procedure utilized with success on one chemical was not effective in application on a second control agent.
Additionally, it has been found that chemicals having a density greater than one are inefficiently disbursed in the aquatic environment with which they are commonly confronted, namely a pond. Such chemicals will tend toward the lowest depths of such a pond, minimizing their concentration at the edges, the more likely breeding area of pests. Suspension of the chemicals throughout such a body of water is desirable.
Woods, in U.S. Pat. Nos. 2,957,803 and 3,184,380, has devised methods of suspending certain water insoluble pesticides. His processes rely critically upon agitation throughout the processes. The constant agitation of the Woods' processes inherently create field preparation complications.
The above processes require complex and expensive preparation. For example, Zoecon SR-10 contains only 10 percent active ingredients. The colloid must be mixed before leaving the factory, causing a multiplication of transportation costs and a reduction in field life.
The present invention protects certain growth regulators from biodegradation while improving their effectiveness by a process capable of efficient practice in the field which forms a stable colloid of chemical particles encapsulated by a fat.